Unlike chemical medicines, biotech drugs are made from living cells so exact copies are not possible, thus the term biosimilar rather than generic as with copies of pills.
Healthcare Triage published this video about biologic drugs:
A biosimilar (also known as follow-on biologic or subsequent entry biologic) is a biologic medical product which is almost an identical copy of an original product that is manufactured by a different company. Biosimilars are officially approved versions of original "innovator" products, and can be manufactured when the original product's patent expires. Reference to the innovator product is an integral component of the approval.
Unlike the more common small-molecule drugs, biologics generally exhibit high molecular complexity, and may be quite sensitive to changes in manufacturing processes. Follow-on manufacturers do not have access to the originator's molecular clone and original cell bank, nor to the exact fermentation and purification process, nor to the active drug substance. They do have access to the commercialized innovator product.
Drug related authorities such as European Medicines Agency (EMA), Food and Drug Administration (FDA), and Health Canada hold their own guidance on requirements for demonstration of the similar nature of two biological products in terms of safety and efficacy. According to them, analytical studies that demonstrate that the biological product is highly similar to the reference product notwithstanding minor differences in clinically inactive components; animal studies (including the assessment of toxicity); and a clinical study or studies (including the assessment of immunogenicity and pharmacokinetics or pharmacodynamics) that are sufficient to demonstrate safety, purity, and potency in one or more appropriate conditions of use for which the reference product is licensed and intended to be used and for which licensure is sought for the biological product.[clarification needed]
In case of a monoclonal antibody-containing medicinal product, such as Remsima, extensive physicochemical and biological characterization for it and its reference product Remicade was conducted in order to demonstrate their highly similar properties. Consequently, EMA have granted a marketing authorisation for only a few numbers of biosimilars since 2006 including a monoclonal antibody which is recently approved. Meanwhile, on March 6, 2015, the FDA approved the United States's first biosimilar product, the biosimilar filgrastim Zarxio.